selecting data for analysis

[Jammin]

I have a column of conductivity measurements overtime at 1/10 s intervals. In preparation for data analysis I isolate each individual event which begins when at the point dye is introduced to the system, the pulse then travels to the measuring device and the recorded conductivity values increase until they peak and then decline back down again. Finally, the event "ends" when the next pulse is introduced. The problem is that the dye input time was not at regular intervals, so the tails of the events are of varying lengths, thus I need to truncate the data in a more systematic manner.  I would like to truncate the data at a point after the peak, somewhere in the tail when the average of 5 consecutive values are < 0 (I need to specify after the peak because sometimes negative values occur before the peak and I need to keep this information). I think using a while loop and running it until the criteria is reached is the way to do it. But I am not sure how to structure my criteria.

thanks

PS I am using Labview 8.6

[aeastet]

Can you post some data and a graph of what you are trying to do? It would make it easier to help with your issue.

[Jammin]

I have attached an example of the data from one event. The graph shows a plot of the data and ~ where I would like to truncate it (done in excel). Hope this clarifies things.

[aeastet · Accepted solution]

How about something like this? I do not look for it to go below 0 five times instead I look for the peak value and then look for it to cross the zero line going down. You can make it more complicated if you would like.

[Andy_C.]

Check this one out

I truncated the arrary at the index where the sum of 5 consecutive numbers are < 0. See if it would work for you.

[Jammin]

Thanks Andy and aestet both vi's are very helpful.

[Jammin]

Sorry aeastet left out an "a".